Maitreyi College, University of Delhi, Delhi, 110021, India.
Department of Zoology, University of Delhi, Delhi, 110007, India.
Fish Physiol Biochem. 2022 Jun;48(3):749-765. doi: 10.1007/s10695-022-01062-8. Epub 2022 Apr 28.
Yolk processing pathways vary in the oocytes of benthophil and pelagophil teleosts. The present study investigated the yolk processing pattern in the oocytes of the fresh water catfish Clarias gariepinus at vitellogenic, maturation, and ovulated stages. This study concludes that during maturation stage, an electrophoretic shift in the major peptide band on Polyacrylamide gel electrophoresis (PAGE) occurs due to a decrease in the size of the yolk protein. The PMF spectrum of corresponding peptides from vitellogenic and ovulated oocytes revealed a difference in the minor ions. A minor difference in the molecular weight of the corresponding peptides occurs due to a difference in their amino acid composition. Maximal activity of the proteases cathepsin D and cathepsin B was observed in the vitellogenic oocytes, thus confirming their role in the processing of yolk. A significant transient increase in the activity of cathepsin B in the mature oocytes also suggests its role in oocyte maturation.
底栖性和洄游性硬骨鱼类的卵黄加工途径不同。本研究调查了淡水鲶鱼（Clarias gariepinus）卵母细胞在卵黄发生、成熟和排卵阶段的卵黄加工模式。本研究得出结论，在成熟阶段，由于卵黄蛋白大小的减小，聚丙烯酰胺凝胶电泳（PAGE）上主要肽带发生电泳迁移。来自卵黄发生和排卵卵母细胞的相应肽的 PMF 光谱显示出次要离子的差异。由于其氨基酸组成的差异，相应肽的分子量存在微小差异。在卵黄发生卵母细胞中观察到组织蛋白酶 D 和组织蛋白酶 B 的最大活性，从而证实了它们在卵黄加工中的作用。成熟卵母细胞中组织蛋白酶 B 活性的显著短暂增加也表明其在卵母细胞成熟中的作用。
